Purgatory by Tunga Han
https://steamcommunity.com/id/delioglan_tunga/

You can hunt each other down by spawning as T or CT in unknown locations.
Visibility is extremely limited, and the sound of rain is intense.
Since the map is not very large, I recommend formats like 1v1, 2v2, or 1v1v1v1.

Have fun!